Recently, there have been prevailing illumination devices whose light sources are semiconductor light emitting elements which have longer lives and which consume a smaller amount of power, such as LEDs. Such illumination devices include an illumination device using a light emission device in which a plurality of LED chips are mounted on an insulating substrate with a high heat-radiating property, such as a ceramic substrate.
Such a light emission device includes a positive electrode and a negative electrode each for supplying power to LED chips. Normally, these electrodes are provided on a substrate so as to be near a light emitting section where LED chips are mounted, in order to allow electric connection with the outside. Conventional examples of materials for such electrodes include Au and AgPt. For example, Patent Literature 1 discloses a light emission device in which such electrodes made of Au are formed on a substrate by plating.
Formation of electrodes by plating requires high costs since it requires a large facility and a large number of steps. In contrast, formation of electrodes by printing is easy to introduce since it requires a smaller facility and a smaller number of steps compared to the formation of electrodes by plating. For this reason, the formation of electrodes by printing is now substituting for the formation of electrodes by plating.
Conventionally, connection between electrodes of a light emission device and external wirings has been made normally by soldering. On the other hand, recently, use of connectors etc. for connection allows easily making electric connection between electrodes of a light emission device and external wirings. A main body of such a connector has a structure which exposes a light emitting section and covers a part of a substrate which part surrounds the light emitting section. The main body has plate-spring like terminals which touch electrodes of the light emission device.